Conventionally, various methods have been proposed for manufacturing coil assemblies for electric rotating machines. For example, in Patent Document 1, there is disclosed a method of simultaneously winding a plurality of coil wires using a pair of plate-like winding cores opposed to each other. Moreover, in Patent Document 2, there is disclosed a method of interlacing coil wires that are shaped by a winding process into a triangular wave shape. According to the method, one coil wire is progressively interlaced with another coil wire by a half turn at a time by repeating the steps of: rotating the one coil wire about its axis by 90° and advancing the one coil wire toward the another coil wire so as to increase the overlap between the two coil wires by a half turn; and rotating the one coil wire further about its axis by 90°.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-176752
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2004-104841